1. Technical Field
The present invention relates to a gyro sensor, an electronic apparatus, and a mobile unit.
2. Related Art
In related art, for example, gyro sensors (capacitance MEMS gyro sensor elements) that detect angular velocities using silicon MEMS (Micro Electro Mechanical System) technologies have been developed. For example, Patent Document 1 (JP-T-2006-515928) has disclosed a gyro sensor including a drive system in which two vibrators (movable structures) are connected by a spring and the vibrators vibrate (also referred to as “tuning-fork vibrate”).
In the case where the gyro sensor is manufactured, using a microfabrication technology such as wet-etching, silicon structures each including a vibrator on which a spring for support and a spring for connection are independently prepared from a silicon substrate provided on a table for manufacture. Then, the springs for connection are connected to each other, and thereby, the gyro sensor having the above described structure may be manufactured.
However, in the manufacturing process, two vibrators are connected for formation, and the connecting part is relatively soft. Accordingly, in the wet-etching processing, at removal of a sacrifice layer by etching, when water of the etchant is evaporated, the connecting part may fall out and stick to the base (hereinafter, referred to as “sticking”) because of the action of the meniscus force due to surface tension, the electrostatic force, or the like.
As a solution to prevent the sticking, it is considered that an anchor is provided in the connecting part of the two springs for fixing and supporting the connecting part and the connecting part is anchored to the substrate. However, in the structure, when the drive system including the two vibrating parts vibrates in anti-phase, the vibration energy exchange between each other is inhibited by the anchor. Here, “anti-phase” refers to movements of two vibrators away from each other or close to each other. Further, “in-phase” refers to movements of two vibrators in the same directions.